Closure for exhaust pipes



June 12, 1956 c. H. HARMON 2,749,832

CLOSURE FOR EXHAUST PIPES Filed April 19, 1954 2 Sheets-Sheet l June 12, 1956 c. H. HARMON 2,749,832

CLOSURE FOR EXHAUST PIPES Filed April 19, 1954 2 Sheets$het fzzzfzzzz or 6/1772 Harzyffarmozz $12 'J/AZMMM 4- 62 2 951 United States Patent CLOSURE FGR EXHAUST PIPES Cline Harry Harmon, Waterloo, Iowa, assignor to WaterlofoI Foundry Company, Waterloo, Iowa, a corporation 0 owa Application April 19, 1954, Serial No. 423,919

9 Claims. (Cl. 9859) This invention relates to a closure device for protecting the upper open end of an upright exhaust pipe for gasoline and diesel engines and the like. Closure devices of this type have the function of excluding rain, snow, dust, dirt and foreign matter from entering the exhaust pipe when the engine is not operating, and function to automatically expose the end of said exhaust pipe when exhaus gases are discharged therethrough.

In previous inventions of this general type, such as shown in United States Letters Patent 2,421,838, and 2,585,548, a counterweighted closure member is secured to the exhaust pipe by means of frame members in the form of rings, or split rings, which frictionally grip the cylindrical wall of the pipe and provide for mounting the closure member on the exhaust pipe. In the use of previous mounting means, the alternate expansion and contraction of the exhaust pipe, caused by the alternate heating and cooling of the exhaust pipe, may operate undesirably to loosen the frictional grip of the ring on the cylindrical wall of the pipe.

In addition, the use of the ring-type gripping means may, in some installations, be awkward or somewhat inaccessible from all around the circumference of the exhaust pipe.

Furthermore, when using the ring-type friction means for securement of the closure flap to the upper end of the exhaust pipe, the closure flap is in engagement with the upper end of the exhaust pipe and by means thereof restricts the mounting ring and flap from completely slipping down the exhaust pipe, although some slipping may occur. When some slipping of the mounting ring does occur, the closure flap is displaced from its normal, horizontal, fully closed position, and is thereafter unable to fully close the upper end of the exhaust pipe.

, In addition to the above mounting problems for these closure devices, there is, in such closure devices, the important and critical problem of providing an eflicient and'reliable pivot mounting for the closure flap. Desirably, such closure devices should be constructed and arranged so that the closure flap is free to move about its pivotal connection in response to the presence or absence of pressure from the exhaust gases issuing from the exhaust pipe. These closure devices, by reason of their location and use, are subject to the natural elements of weather and, in addition, are subject to relatively high temperatures as the exhaust gases pass from the exhaust pipe, and hence the metal parts of the closure device are subject to an unusually wide range of temperature conditions. It sometimes happens that the pivotal connection of the closure flap becomes rusty, or impaired in some other manner, to the extent that the closure flap will not readily move in response to the presence or absence of pressure from the exhaust gases, and thus fails to. perform its intended function. I

One previous attempt to provide a proper pivotal mounting for this type closure device is disclosed in United States Letters Patent 2,585,548 and requires the use therein of a special bushing for the pivot pin and also requires adjustable trunnions. Furthermore, with the use of the bushing and trunnion arrangement shown in said patent, there is usually some lateral play between the parts and such lateral movement will result in increased and rapid wear of the pivot bearing.

The present invention is directed to an improved means for mounting the closure device on exhaust pipes and to an improved pivotal mounting for the pivotally mounted closure flap of the closure device.

Thus, one object of this invention is to provide novel and improved means for securing a closure device, of the general type described, to the exhaust pipe of an internal combustion engine.

Another object of this invention is to provide a closure device for exhaust pipes having novel means for securement to an exhaust pipe which does not require accessibility to the exhaust pipe from all around the circumference thereof, and which requires a connection of said means for securement to only a relatively small portion of the circumference of the exhaust pipe.

A further object of this invention is to provide mounting means for a closure device for exhaust pipes which completely eliminates any possibility of slipping of the mounting means down the exhaust pipe, and thereby insures that the closure flap will always be in a position to fully close the upper open end of the exhaust pipe.

Still a further object of this invention is to provide a novel, simplified, and inexpensive pivotal mounting for the closure flap of a closure device for exhaust pipes.

And another object of this invention is to provide a novel pivotal mounting for the closure flap of a closure device for exhaust pipes which obviates the above noted problems, eliminates the provision of special bushings and adjustable trunnions, and reduces lateral movement of parts and wear in such a device.

Further objects and advantages of this invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

A preferred embodiment of this invention is shown in the accompanying drawings, in which:

Figure l is a top plan view of a closure device for exhaust pipes having the novel attaching means for securement of the closure device to the upper end of the exhaust pipe;

Figure 2 is a side elevation view of the closure device of Figure 1;

' Figure 3 is an end elevational view taken looking from the right of Figure 2;

Figure 4 is a cross-section view taken on line 4-4 of Figure l, and, in addition, shows the closure device of Figures 1-3 with the closure flap in an open position; Figure 5 is a cross-section view taken substantially on line 5-5 of Figure 4;

- Figure 6 is a perspective exploded view of the mounting means for the closure device shown in Figures 1-5;

Figure 7 is a side elevation view similar to Figure 4 showing a closure device for exhaust pipes provided with the improved pivotal mounting of this invention; and

Figure 8 is an enlarged cross-section view taken on line 88 of Figure 7 showing the details of the improved pivotal mounting.

Referring now to the figures, and to the form of the invention shown in Figures 1-6, there is illustrated in said figures, the upper end of an exhaust pipe 10 of an internal combustion engine, which exhaust pipe 10 terminates at an upper terminal edge 12. The closure device for attachment to the upper end of the exhaust pipe 10 broadly comprises a first frame member 14, a second; frame member 16, and a. counter-weighted closure flap;

18' pivotally mounted on the first frame member 14.

Referring to the first frame member 14, said member has a smooth horizontal bore 20 therethrough, which horizontal bore 20 provides a bearing surface for a pivot pin, or bolt, 22 that is carried by the counterweighted closure fiap 18. The frame member 14 also has a bore 24 therethrough which is, disposed at anangle of approximately 45" to the horizontal, as can best be. seen in Figure. 4, and said bore 24 being adapted to receive a threadedbolt 26 therein. The lower end of the bore 24 terminates in an enlarged recess 28' adapted to receive therein the head of bolt 26. The bore 2.4? is of greater diameter than the threads of bolt 26 so that bolt 26 is rotatably carried by the frame member 14.

The. surface, 30 of said frame member 14 which is adapted to engage the exhaust pipe. 10. is concave to conform to the, outer surface of the exhaust pipe. The member 14 also. provides. a flat inclined bearingsurface 32 against. which a. portion. of the. second frame member 16 is positioned for sliding movement therealong. The surface 32 is located in a plane substantially parallel to the axis. of. bore 24.

The second. frame member 16. is shaped to broadly define anv elongated. clamping portion 34, an edge engaging; portion 36, and a portion 38 for operative. assoeiation. with the threadedbolt 26. and with. the first frame member 14. The elongated clamping portion 34 is adaptedto enter the exhaust pipe through the open end thereof and to engage the inside of the exhaust. pipe at a point opposite the first frame member 14. The surface of the clamping portion 34 which engages the ex? haust pipeis convex to conform to the inner surface of the exhaust pipe, and, in addition, has a series of arcuate serrations 40 thereon for obtaining better gripping and clampingenga-gement with the inner wall ofthe exhaust pipe. 10. The edge engaging. portion- 36 of the second frame member 16 overlies and engages the upper terminal edge 12 of the exhaust pipe and is, operative to prevent the mounting means for the closure flap from moving; downwardly along the exhaust pipe.

The portion 38 of the second frame member 16 has a threaded" bore 42 adapted to have the bolt 26 threaded thereinto. The portion 38 of frame member 16 also has an. inclined bearing surface 44 for engaging the inclined surface 32 of the first frame member for sliding movement thereal'ong, when the frame members are in operating position, as shown in Figure. 4. The inclined surface 44 disposed in a plane parallel to the axis of bore 42. The engagement of inclined surfaces 44 and 32 provides that the bore 42 in the second frame member may be maintained in axial alignment with the bore 24 inthe first frame member as the frame members 14 and 16 are moved toward and away fromeach other by the operation of the threadedbolt 26.

From the above description it will be seen that by loosening thebolt 26'and backingit off, the space between the clamping portion 34 ofthe second frame member and the wall engaging surface 30; of the first fi'ame member can be variedso that the frame members mayv be slipped over the upper edge of an exhaust pipe. There? after, by tightening upon the threaded bolt 26, the=frame members are'drawn toward each other so as-to positively clamp; the frame members. ontothe upper. end of the ex: haust: pipe 10-, said frame members also cooperating with the upper: terminal edge 12- of the exhaust pipe so. as to prevent any downward movement of the framemembers relative to-saidupper end of the exhaust pipe. To: prevent any inadvertent loosening of the threaded bolt 26, a; look washer 46 may be. provided;

- Referring-now to the counterweighted closure: flap; 18, said: closure flap, includes a: substantially circular: portion 48 adapted for overlying. the upper end of the exhaust pipe and being provided; at: itsedge. with adepending flange-.49. While-Abe circular portion 48 isshown over-- lying the upper end of a closure pipe of one diameter, it will be seen that said' circular portion 48 may overlie pipes of smaller or greater diameter, such as indicated by the dash lines 50 in Figure 5. Secured to the circular portion 48 of the flap 18 is a tail portion 52 constituting a counterweight, the undersurface of which is recessed as indicated at 54 for accommodating therein a portion of the first frame member 14. The recess 54 is enlarged at 55 to provide clearance for the edge engaging portion- 36 of the second frame member 16, as best seen in Figure 2. The tail portion 52; includes a pair of spaced side walls 56 which partially define the recess 54 within which said portion of the first frame member 14 is positioned. The pair of spaced side walls 56 carry the bolt, or pivot pin, 22 which extends through and is journalled in the bore 20 in the first frame member. The bolt 22 may be appropriately secured to the counterweighted closureflap 18, such as by means of a nut 58 and lock washer 60;

In the particular design of the novel pivotal mounting. of the counterweighted closure flap 18, which novel pivotal. mounting is shown in Figures 7 and 8, the side walls 56 of the counterweighted closure flap 18 are shown as carrying a bolt 22 having a head 64 at one end and being threaded, as at 66, at its other end. The bolt 22 is appropriately secured to the walls of the counterweighted closure flap 18 by means of a nut 58' and lock washer 60 The first frame member 14' has a smooth. bore 20 therethrough, within. which the bolt 22. is journalled for pivotal: movement. The frame member 14' has formed therein, at each end of bore 20', an. enlarged: recess 68 which is disposed coaxial with bore. 20 A; coiled spring 7i) is positioned in the recess 68 and engages the frame member'14 at one end thereof and the adjacent end wall 56.- ofthe counterweighted closure flap. 1-8 at the other end thereof, so as to provide resilient means between the frame member 14' and: each side wall 56. Each. coil spring 70 ispositioned concentrically of the shank of bolt 22. It will be seen that the springs 70- cooperating with the walls 56' of the closure flap serve to maintain said walls 56 spaced fromframe member 14 and thereby eliminates. any undesirable Wear which. might ordinarily take place between: saidpar-ts ifthere was rubbing; therebetween.

The bolt 22: is bored: axial fromthe-head end thereof to. provide a channel 72 which begins at the head of. the bolt and. runs axially of -thebolt to a. point substantially midway between the ends of bore 20- in frame member 14 A. transverse, or radial, bore 74 then communicates the axialv bore 72 with the bore 20 in the frame member 14'.

A grease. fitting. 76,. the details of which are well known, is. mounted. by means of threads 78 in the head 64 of the bolt. 22 and is in. communication with the borev '12, and thus providesmeanstfor. supplying. lubricant tothepivotal mounting: formed by bolt 22 beingjournalled-in:bore:20. The;passageways-72 and 74. not only provide means for introducing grease into the bore 20' but also serve asareservoir for additional lubricant.

While; there has-been shown. and described a particu-. lar embodiment: ofthis invention, it will be obvious to those skilled in; the art. that various changes and modificationss maybe made therein without departing from. the invention and, therefore; it is'intended in: the appendedclaims to cover all such changes. and modifications asfall-within the' true spirit andscope of the invention.

What- I- claim'as new, and desire tosecure-by- Letters- Patent of the'United States, is:

1. In a closure device of the characterdescribed. adapted'to be secured" to the upper'endofan upwardly extending exhaust pipe, a first frame member adapted to engage said exhaust pipe on the outer. side. thereof; a counterweighted closure. flap. pivotally mounted on said frame member, asecond frame member carried by: said' first frame member and defining a clamping portion adapted to enter said exhaust pipe and engage the inside thereof, means including a bolt carried by one of said frame members and mounted for rotation therein and threaded to the other said frame member for urging said frame members toward each other to clampingly secure said frame members to said exhaust pipe, and the surface of said clamping portion which is adapted to engage the inside of said exhaust pipe having serrations formed thereon.

2. In a closure device of the character described adapted to be secured to the upper end of an upwardly extending exhaust pipe, a first frame member adapted to engage said exhaust pipe on the outer side thereof, a counterweighted closure fiap pivotally mounted on said frame member, a second frame member carried by said first frame member and defining a clamping portion adapted to enter said exhaust pipe and engage the inside thereof, means including a bolt carried by one of said frame members and mounted for rotation therein and threaded to the other said frame member for urging said frame members toward each other to clampingly secure said frame members to said exhaust pipe, and an edge engaging portion on one of said frame members being positioned to extend above and laterally across a portion of the upper terminal edge of said exhaust pipe and being adapted to engage said upper terminal edge.

3. In a closure device of the character described adapted to be secured to the upper end of an upwardly extending exhaust pipe, a first frame member adapted to engage said exhaust pipe on the outer side thereof, a counterweighted closure flap pivotally mounted on said frame member, a second frame member carried by said first frame member and defining a clamping portion adapted to enter said exhaust pipe and engage the inside thereof, means including a bolt carried by one of said frame members and mounted for rotation therein and threaded to the other said frame member for urging said frame members toward each other to clampingly secure said frame members to said exhaust pipe, the surface of said first frame member which is adapted to engage said exhaust pipe being concave to conform to the outer surface of the exhaust pipe, and the surface of said second frame member which is adapted to engage said exhaust pipe being convex to conform to the inner surface of the exhaust pipe.

4. In a closure device of the character described adapted to be secured to the upper end of an upwardly extending exhaust pipe, a first frame member adapted to engage said exhaust pipe on the outer side thereof, a counterweighted closure flap pivotally mounted on said frame member, a second frame member carried by said first frame member and defining a clamping portion adapted to enter said exhaust pipe and engage the inside thereof, and means including a bolt carried by one of said frame members and mounted for rotation therein and threaded to the other said frame member for urging said frame members toward each other to clampingly secure said frame members to said exhaust pipe.

5. In a closure device of the character described adapted to be secured to the upper end of an upwardly extending exhaust pipe, a first frame member adapted to engage said exhaust pipe on the outer side thereof, a counterweighted closure flap pivotally mounted on said frame member, a second frame member carried by said first frame member and defining a clamping portion adapted to enter said exhaust pipe and engage the inside thereof, means including a bolt carried by one of said frame members and mounted for rotation therein and threaded to the other said frame member for urging said frame members toward each other to clampingly secure said frame members to said exhaust pipe, and said frame members having surfaces in cooperating engagement with each other for accommodating sliding movement between said frame members, said cooperating surfaces being disposed in a plane parallel to said bolt.

6. In a closure device of the character described adapted to be secured to the upper end of an upwardly extending exhaust pipe, a first frame member adapted to engage said exhaust pipe on the outer side thereof, a counterweighted closure flap pivotally mounted on said frame member, a second frame member carried by said first frame member and defining a clamping portion adapted to enter said exhaust pipe and engage the inside thereof, means including a bolt carried by one of said frame members and mounted for rotation therein and threaded to the other said frame member for urging 'said frame members toward each other to clampingly secure said frame members to said exhaust pipe, said frame members having surfaces in cooperating engagement with each other for accommodating sliding movement between said frame members, said cooperating surfaces being disposed in a plane parallel to said bolt, said first frame member having a concave portion to conform to the outer surface of the exhaust pipe, and said clamping portion of said second frame member being convex to conform to the inner surface of the exhaust pipe.

7. In a closure device of the character described comprising a frame element adapted to be mounted on an exhaust pipe, and a closure flap pivotally connected to said frame element and adapted to normally cover the open end of said exhaust pipe and movable to an open position by the pressure of the exhaust gases discharging through said pipe, said flap having a laterally extending counterweight for counterbalancing a portion of the overhanging weight of the flap, said counterweight having a cavity formed in its underside between a pair of laterally spaced apart walls, said flap being mounted on said frame element with said frame element projecting into said cavity between said walls; the improvement wherein said pivotal connection comprises an elongated bolt extending through said spaced apart walls and being carried thereby, said frame element having a bore therethrough within which said bolt is pivotally and slidably mounted, said bolt having an axial bore therein extending from one end of the bolt, a radial bore in said bolt communicating said axial bore with said bore in the frame element, a grease-fitting in said axial bore at said end of the bolt, and resilient means positioned between said frame element and each of said spaced apart walls.

8. In a closure device of the character described, comprising a frame element adapted to be mounted on an exhaust pipe, and a counterweighted closure flap pivotally mounted on said frame element and adapted to normally cover the open end of said exhaust pipe and movable to an open position by the pressure of the exhaust gases discharging through said pipe, said counterweighted flap having a cavity formed therein between a pair of laterally spaced apart walls and said frame element being positioned within said cavity; the improvement wherein said pivotal connection comprises an elongated bolt extending through said spaced apart walls and being carried thereby, said frame element having a bore therethrough within which said bolt is pivotally and slidably mounted, said frame element having a pair of recesses, of greater dimension than said bore in the frame element, therein at opposite ends of said bore and coaxial therewith, and a coil spring in each of said recesses surrounding said bolt and engaging, at opposite ends thereof, said frame element and the adjacent wall of said counterweighted flap, whereby said spaced apart walls are positioned with respect to said frame element.

9. In a closure device of the character described, comprising a frame element adapted to be mounted on an exhaust pipe, and a counterweighted closure flap pivotally mounted on said frame element and adapted to normally cover the open end of said exhaust pipe and movable to an open position by the pressure of the exhaust gases discharging through said pipe, said counterweighted flap hav- 7 ing a cavity formed therein between a pair ofi laterally spaced apart walls and said frame, element being positioned within said cavity; the improvement wherein said pivotal connection comprises an elongated bolt extending through said. spaced apart wallsand beingcarried thereby, said frame element having a bore therethrough within which. said bolt is pivotally and slidably mounted, said frame element having a pair of recesses, of greater'dimension than; said here in the frame element, therein at opposite: ends of said bore and coaxial therewith, a coil spring 10' frame portiont-sai'drbolt having an axial bore therein ex- 15 8 tending from one end of the bolt, a radial bore in said bolt communicating said axial bore with said bore in the frame element,- and a grease-fitting within said axial bore ats'aid end of the bo'lt'.

References Citedin the file of this patent UNITED STATES PATENTS 1,218,424 Lindsey Mar. 6, 1917 1,761,339 Hauser June 3, 1930 1,924,586 Zerk Aug. 29, 1933 2,421,838 Harmon et al. June 10, 1947 FOREIGN PATENTS 421,214 Great Britain July 3, 1935 

